The cornering fatigue test is intended to determine the structural performance of the wheel for normal highway use on passenger cars, light trucks and multipurpose vehicles. Wheels are mounted on a testing machine which simulates cornering under heavy loads.
The wheel is placed at an extreme angle and is heavily loaded (or pressed against) with a high amount of weight. These cornering fatigue tests exceed any stresses realized from normal road use, but they are designed to meet the standards set forth by SAE (Society of Automotive Engineers).
Wheel Terminology Explained